Electrically driven speed reducing power unit



March 16, 1954 A, c. JOHNSON ELECTRICALLY DRIVEN SPEED REDUCING POWER UNIT 3 Sheets-Sheet 1 Filed May 19, 1950 INVENTOR. Ar/fiar C 75/2/78 a? /A 'MM Q Jzzornfy March 16, 1954 A. c. JOHNSON 2,672,170

ELECTRICALLY DRIVEN SPEED REDUCING POWER UNIT Filed May 19, 1950 3 Sheets-Sheet 2' 1N VEN TOR. fir/lv a) 6 johns an Afton/7g March 16, 1954 Q JOHNSON 2,672,170

ELECTRICALLY DRIVEN SPEED REDUCING POWER UNIT Filed May 19, 1950 3 heets-Sheet 3 /4 I N V EN TOR.

/4r'z%ar fohnsan I44 BY/Zz Alforney Patented Mar. 16, 1954 UNITED srA-res rarest err-res EEE CTRICALLY DRIVEN SPEED REDUCING POWER UNIT Amiurfo. .Iiflins'on, san'Mariho, Calif Application May'lil 1950, Serial'No. 162,943 1? claim. (01. 143343)" This inventioni has to; do with. apower unit and: it is ageneral object ofthe; invention: to provide a: structure? or unit particularly useful in; wood working; machinery: or the like;

There are various-machines in which elements such"; as toolsare; operated by electric; motors-2 For; example" in the wood, working industry var ou's' operat ons are? performed by machines with motor 'drivencutters, and: for: different operations th'e cut't'ers are operated at; different speeds, thus ordinarily requiring: different machines for different operations I It: is: a gene'rali obj ect. of this invention: to: pro vid'e practical: improved power unit or motor applicable to a Wood working machine such-for t example; as a machine wherein a tool driving motor: is carried on anzarmthrough; a mounting which enables the;m'otor. to; be arranged in various'mannerswith: reference to 'awork carrier.

Another object OfthiStiIlVfi'ltiOIli is to provide alunitlof the general: character-referred to having a; shaft projecting; from one end of the structure eperat'ingvat on'espeed whilea secondi shaft: projects from the" other end of, the-structure and operates: at? a." materially difierent speed: Ina typical application of. the; invention. the first mentioned shaft may be apart of the'motor shaft operating: at: motor speed. whereas the second shaft. is" operated through: a: speed reducing mechanism and operates duced speed.

Another object; of: this invention iS-T toprovide as power unit' of? the general: characterreferredsto wherein'speedreduction" is gained through. a belt driveandthe: drive iSfSUCh'a S to involve but/fewsimple dependable parts arranged in a simple compact. formation.

It? is; another: object of this invention to'providev'a'drive'unit'of-the generalcharacter referred to inwhich the belt drive or the speed reducing I mechanism is: readilyadjustable toset the belt thedesired manner; A further objectaot theinvention is: to provide a: drive unit of the general character referred to including: asuitable" housing encasing the principal' working: parts and which-may serve as a:

support -for a tool guard if desired.

It is a further object: ot the" inventionto provide power; unit of the general character re ferred to and-a mounting means'thereforwherebyi the; power unit is? variable as toposition, for instance; shiftablef end for end as circumstances may require.

The-mechanism embodying the present: inventionwis-particularlypracticaleas appliedetoa wood at a substantially re-= rocatinge armoverlying the work working; machine wherein there is a worksupportor carrier and ahorizont'ally disposed recipsupport' and carryingthe power unit through a mounting which enables the unit to be moved bodily'aboiit a vertical axis. The arm may be supportedb'y'a" carrier which is supported by a post mounted to rotate and reciprocate ascircumstances require. The power, unit embodying the present inventio-nis preferably carried by aha-nee off a' bracket depending from the arm so that" it is beneath the forward end portion of the arm and over-liesthe work carrier.

The power unit preferably involves an electric motorwith a case with an outer end having'an" inwardly projecting boss carrying'a bearing and aninner end with an outwardly projecting" boss carrying a-bearing. A motor, shaft is supported in the'bearings and has a threadedtool carrying end projecting from the first mentioned bearing and has an extension of substantial-lengthpro jecting from the second bearing. Thespeed reducing mechanism provided by the" invention involves a drive pulley fixed on the extension" of the motor shaft an'cla driven pulley oarried'by suitable bearing means supported by a carrier secured to the end 'of themoto'r case. from which the shaft extension projects. A" tool carrier providedon the driven pulley and abelt operates over or between thepulle'y's'. A housing prererably encases the pulleysand t "e. beltjand a guard maybe carried'by. the housingto shield a cutter operated by'thedrivenpulley'. The carrier'sup porting the drivenvp'ulley is adjustable relative to? the motor case so the. driven pulley can" be adjusted rela'tive to the drive pulley to properly set the pulleys relative. to thebelt';

Mounting means supports the power unit from the depending flangeof the bracket carried by the arm' of" the machine and is such that the, motor can rotated about a horizontal axis to any desired position as circumstances may require. The mounting preferably'involve's a" boss on the motor case with a reduced extension'rotatably carried iii an'operiing in'the flangewhich depends from the arih A retainer, preferabl'yja' disc-shaped plate, holds'the'boss' extensioninth'e bore. provided in the" flange; Releasable stop means is provided'to holdthepower unit mounting in various rotativefpositions endangemeans is. provided for setting the. powerunit against shifting; or movement relative to as: supporting flange. p

The various objects and features" of my" in vention will be fullv'und'erst'oocffrom the follow- 3 ing detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of a typical wood working machine embodying the present invention showing the machine with the power unit operating a cutter in the form of a disc saw and with the parts positioned for typical use of the saw. Fig. 2 is a view similar to Fig. 1 showing the power unit operating a router type cutter and with the parts of the machine positioned suitable for operation of this type of tool. Fig. 3 is an enlarged view of a portion of the mechanism shown in Fig. 2, being a view taken as indicated by line 3-3 on Fig. 2. Fig. 4 is an enlarged longitudinal sectional view of the power unit, being a view taken as indicated by line Q on Fig. 1. Fig. 5 is a vertical sectional view taken as indicated by line 5-5 on Fig. 4. Fig. 6 is a plan section taken as indicated by line t-% on Fig. 2. Fig. 7 is a sectional view taken as indicated by line 1-4 on Fig. 4. Fig. 8 is a detailed sectional view taken as indicated by line 3-3 on Fig. 5, and Fig. 9 is a detailed sectional view taken as indicated by line 3-3 on Fig. 6.

The power unit provided by the present invention and the mounting means provided for such unit can be applied to or incorporated in various machines and in machines intended for various purposes or classes of work. The present invention is particularly useful and practical as applied to wood working machinery and in this disclosure it will be referred to as applied to a common type of wood working machine in which it can be used to advantage.

The machine illustrated in the drawings involves, generally, a rigid horizontally disposed base A having a work support or carrier B mounted on its forward portion. A guide C projects upwardly from the rear portion of the base and carries a post D. The post is rotatable in the guide and can be reciprocated therein and it carries a head E at its upper end. The head supports a horizontally disposed arm F so the arm can be reciprocated. The arm is provided at its forward end with a mounting for the structure provided by the present invention and in the particular case illustrated this mounting involves a block 13 fixed on the arm and an L-shaped bracket H secured to the block In and depending therefrom. The bracket has a top horizontal flange I2 secured to the under side of the block it by a vertical coupling pin 13 and has a depending vertical flange li that extends downwardly from one edge of the flange $2. The general mechanism thus far referred to is more fully described and is the subject of my copending application entitled Wood Working Machine With Motor Driven Tool and Shiftable Work Carrier, Serial No. 162,945, filed on even date herewith, now abandoned.

The power unit provided by the present invention and shown generally in Fig. 4 of the drawings involves an electric motor M and a speed reducing mechanism S.

The motor M may, in practice, he of any suitable form or type and for purposes of example I have illustrated a typical motor involving a cylindrical case 23 closed at its outer end by an end 2! and at its inner end by an end 22. A central motor shaft 23 is supported in the case by means ofsuitable bearings 23 and 25 carried by the ends 26 and 22, respectively. Inthe preferred arrangement the bearing 24 is-carried in an inwardly projecting boss 26 on the end 2i while the bearing is carried in an outwardly projecting boss 21 on the end 22. The bearings are shown as antifriction bearings of typical construction and, in accordance with the invention the motor shaft 23 has an end 23 projecting beyond the bearing 24 so that it is exposed to carry a suitable tool desired to be operated by the motor. In the particular case illustrated the projecting end 23 of the motor shaft is suitably threaded so that any standard tool or connecting part can be readily attached thereto.

As above pointed out the present invention is in no way concerned with the details of the motor. However, for purpose of example the motor is shown as including a field element 33 carried in the case 20 and a rotor 3| on the shaft 23 and within the field. A suitable commutator 32 is provided on the shaft and a power carrying cable 33 enters the motor through a suitable opening 34 provided in the case.

The speed reducing mechanism S provided by the present invention is preferably mounted on or joined to the motor M as a rigid or permanent part thereof so that the motor and mechanism S form a compact unit. In the particular form of the invention illustrated the speed reducing mechanism S involves, generally, a drive pulley 36 operated by a motor M, a driven pulley 31 operated from the pulley 36 by a belt 38, suitable bearing means 33 supporting the driven pulley, a carrier d3 supporting the bearing means, and a tool holder or mounting 4| for carrying a tool so that it is driven by or mounted on the driven pulley.

The drive pulley 35 is preferably operated directly by the motor shaft 23 in which case the motor shaft is provided with an extension of substantial length projecting beyond the bearing 25 carried in the boss 21. In the particular case illustrated in the drawings the pulley 36 is considerably smaller in diameter than the driven pulley 31 and it is carried directly on the shaft extension 45 to which element it is fixed by means of a key 41. The shaft extension 45 has a threaded end portion 48 carrying a nut 43 which serves to retain the pulley 36 of the extension 45. As shown in the drawings the motor shaft may have a shoulder 50 against which the pulley 46 is held by means of the nut 49.

The carrier 40 for the bearing means 39 which supports the driven pulley is shown as involving a plate 53 arranged against the outer side of the end 22 of the motor M and a boss 54 projecting from the plate 53 to carry the bearing means 39. The plate 53 is shown as being of substantial extent so that it, in effect, covers the entire outer side of the end 22 in which case it is provided with an opening 53 passing or accommodating the boss 21 that carries bearing 25. Suitable fastening means 58 secures the plate 53 to the end 22 of the motor so the plate can be suitably shifted relative to the motor. In the preferred form of the invention the means 58 involves clamp screws 59 engaged through parallel slots 60 in the plate 53 and threaded into the end 22 of the motor (see Fig. 5). Heads 6! on the clamp screws 59 engage the outer side of the plate 53 through washers 62 so that when the screws 59 are tightened the plate 53 is clamped against the end 22 of the motor. The slots Ell in the plate 53 are parallel and. extend in the direction that the driven pulley is removed or offset from the motor shaft thus allowing the plate 53 to be shifted or adjusted relative to the motortovarythe position; of the 'dr-ivenpulley relativefto the drive pulleywhich is on the motor shaft:

The boss- 54 provided on plate 53 isshown' as anintegral extension on protection occurring on the I plate and in the particular case illustrated the bearing means: 3&3 involves: spaced: antii-fric-l tiom bearings: E55 arranged; within; the: boss. 51h The boss: is shown as provided. with: a. bore: flit. terminating in. a; shoulden- 6r. T1155 bearings; 652 are: held; apart: by: suitable. spacers; 6t and: the; assemblyiformed. by; the abearings; and 5 the;spaeers; is held: against; the; shoulden 6?; by; a clamp; mi lihthreadeddn theiouter 'BlldOf thezborez 6,6.

The? driven: pulley Whit .is: substantialln larger in. diameter; than; the rive; puller 36 has av. drawn-shaped belt; arr portion; 8a sure remind-ins theebqss 551" with nwhi h th -bearing; means-damm d; he pulley 3I-hasanl d pl e 81; fixed toione; end of: the drum; tdandvlccated immedi t ly yond; theouter end oithe boss 54;. spindle dz isrcarriedby the-plated] Q0115. centric with the. drum 80. and. extends into; the bearingscairiried-intheboss 54. Through this onstruc ion, the ltcarry na rum tit-surround: ing; the boss. 5tv is effectively supported; by the bearings located within he boss.

Erom. the, foregoing, description. and from examination; of, Fig. 4;.of. the draWingS it will be observed that.th,e1pul1eys,,3.6 andtl' are in line withithedriven, pulley laterally offset from the drive pulley. The belt 38 effects the desired drive from; the drive? pulley to the driven pulley and may be asirnple flexible belt engaged over or around the pulleys in the manner clearly illustrated in Figs. 4 and 710i the drawings. It w-illbe understood from the foregoing description hove the-carrier 40. which supports the driven pulley through the construction just described can be adjusted to vary. the tension on the belt sothat: the mechanism operates in the; desired manner.-

The means 4| prov-idedtc carrya suitabletool so thatit is: operated by the driven pulley. may, in" practice, vary, depending upon the type or character of tool to-beoperated. In the case illustrated this means isshown as: an extension or projection 95 on the outer side of the plate and located concentrically with the spindle 32. The projection 91 is such as to receive a suitable tool, say, for instance, a saw 9|, and it is threaded so that a retainer or nut 92 can be engaged on it to clamp the tool in place. In the case illustrated the outer side of plate 8| is provided with a tool receiving shoulder 93 and an annular tool clamp 94 is carried on the projection 90 to oppose the shoulder 93 and to be operated by the nut 92 so that the tool 9| is clamped tight against the shoulder 93. The particular tool 9| illustrated in the drawings is a rotary or disc-type saw, being a tool of a type that can be advantageously operated at a speed considerably less than that at which the motor shaft 23 operates.

In carrying out the present invention it is preferred to provide a housing 95 to encase the principal working parts. In the drawings the housing 95 is shown as involving an annular shell 96 corresponding in diameter with the plate 53 and having one end engaged with the peripheral portion of the plate so the shell surrounds or encases the belt drive mechanism hereinabove described. An end plate 91 is carried by the other end of the shell 96 to enclose the belt drive as shown in Fig. 4 of the drawings. Where a tool such as a disc saw is employed it may be desired to provide a 5 the axis of the. extension. I I I'.

guard- IIIO. In the: case illustrated theguardie shown carried by the housing and hasi a rim II which is engaged around the-shell- 96 ofthe housing and is secured thereto by suitable screwr fasteners I02 A-sideplatelll3 isca-rriediby the the mount-ing---means involvesaboss I It (Fig: 8)

onone side ofthe motor casein, a round exten sion H I= on the bossrotatable in a bore I'I Zinthe flange- I4; and a-retainer I I 3holding theextension III in; the bore. In thecase illustrated in the drawingsthe boss I Ii=is of substantial size and is formed integrally with-themotor casewvhile the extension H I is smaller-than the boss leaving a shoulder; portion I I5 on thebossto bear against the inner side of: the flange I4 The extension I I I is-turned or round; so that it rotates freely in the bore |I2 and it extends through'the boreso thatits outer end I I-Tis flushwithlthe-outenface or side IIB'of the flange I4; The retainer I I 3*ls a,round or disc-shaped plate that may-'betsuit ablysecured to theouter-end I I lof the extension I'I'I as by suitable fasteners I28: The plate-cram tainer H3 is considerablylarger. in diameter than the extension Iii so that it projects beyondthie extension and overlies the vouter face I "I def-flange I 4.. Itis preferredthat'the retainer I-I3beround and it isrsecuredito the extension II Iso thatitiS concentric therewith; In the case illustrateda suitable centering projection I2'5is providedfon the extension II I to centertheretainer I'I3on theextension,

With the construction just,describediitjwilrbe apparenthow theunit; formedby the motor and speed'reducing mechanism is .rotatably mounted onthe flange I4;s o that'it is freely rotatable about The mountin iis such ,thatthe unit'formedby the motor and mecl'ie an fimsfcan berotatedythrough 860."

Releasable stop, means I351, serves to holdthe mounting 4 just. described inlpredeterminednosi tions. As shown in 3,.oi.'the..,drawings.the means I30 may involve astop dog I31 mount'e'don the flange I4 by means of a pivot pin I32. The dog cooperatively engages one or more peripheral notches I33 in the retainer H3. When the dog is engaged with a notch in the retainer the structure is held against rotation or operation, whereas, when the dog is lifted or released the mounting is free to operate allowing the motor to turn to any desired position.

Lock means I 4i! serves to set or lock the mounting of the unit in any desired position. The particular lock means illustrated in the drawings is shown in Figs. 6 and 9 of the drawings. The flange I4 is provided with a cut or opening I4I extending to the bore H2 and lugs I42 project from the flange at opposite sides of the opening I. A clamp screw I43 is threaded to one of the lugs and carries a head I44 that bears against the other lug. The head is shown as an adjustable structure made up of a part I45 threaded on the screw I43 and a lock nut I46 threaded on the screw and locked against the part I45. The part I45 is provided with a suitable operating handle I41. Through the construction just described the part I45 and the nut I46 can be so set or adjusted 7 to the screw I43 as to bring the handle I47 in the desired position when the means I40 is set looking the short extension III against rotation in bore H2.

The present invention provides for holding the parts against operation or rotation to facilitate operation of nuts or the like on the parts 28 and 90. In the form of the invention illustrated the drive pulley 36 has an end portion I50 (Figs. 4 and 5) forming a wrench receiving part. The extension I50 is shown as having fiat sides I5I for the reception of a simple wrench I52. The housing is provided with an opening to admit a wrench to the part I50. The shell 96 of the housing is shown provided with an opening I55 located so that the wrench I52 can be inserted to engage the part I50, as shown in Fig. 5 of the drawings. When the wrench I52 is engaged as shown in Fig. 5 nuts or like parts can be threaded to or removed from the threaded parts 28 and 90 without the threaded parts rotating.

From the foregoing description it will be apparent that the invention provides a unit with two rotating tool carrying parts, namely the parts 28 and 90, which parts rotate at different speeds. The driven pulley being substantially larger than the drive pulley the tool carrying part 90 rotates considerably slower than the motor shaft 23 and therefore the part 28 of shaft 23. With this variation in speed of operation of the parts 28 and 90 the user is able to operate tools such as routing tools, carving tools, or the like, requiring high speed operation, by means of the shaft part 28, whereas saws or the like can be advantageously operated by the part 90. By reason of the mounting means mounting the tool operating unit on the support or flange I4 the tool driving unit can be turned or positioned in any desired manner as circumstances may require. The drawings show two typical positions into which the unit can be arranged, Fig. 1 showing a position suitable for operation of a saw which may be applied to part 90, while Fig. 2 shows a router or routing tool applied to the shaft part 28.

Having described only a typical preferred form and application of my invention, I do not wish to be restricted or limited to the specific details herein set forth, but Wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claim.

Having described my invention,- I claim:

A tool driving unit of the character described including, an electric motor having an elongate case and a shaft with an end portion projecting from and accessible at one end of the case adapted to receive a tool and an extension projecting from the other end of the case, a plate slidably mounted against the outer side of said other end having an elongated opening through which said extension projects, and a speed reducing mechanism including a drive pulley fixed on the shaft extension, a driven pulley rotatably mounted on said plate, said driven pulley being larger than said drive pulley and having a hollow belt receiving portion, a belt on said pulleys tensioned by slidably moving said plate in a plane perpendicular to the axis of said shaft extension, means for locking said plate in slidably adjusted position, wrench receiving means on said drive pulley, means on the driven pulley at one end thereof and adapted to carry a tool, a housing completely enclosing the belt and pulleys leaving the means on the driven pulley exposed, said housing having an access opening aligned with said wrench receiving means so that a wrench passed through said opening to engage said wrench receiving means will prevent rotation of said drive pulley and, correspondingly, said driven pulley, and enable the placing or removing of a tool on said means at one end of said driven pulley.

ARTHUR C. JOHNSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 741,034 Hazleton Oct. 13, 1903 1,568,328 French Jan. 5, 1926 1,716,484 Carrey June 11, 1929 1,806,528 Fegley et al. May 19, 1931 1,883,392 Moll Oct. 18, 1932 2,137,921 Matthews Nov. 22, 1938 2,154,745 Hedgpeth Apr. 18, 1939 2,197,207 Demers Apr. 16, 1940 2,242,336 Atwood May 20, 1941 2,284,441 Murad May 26, 1942 2,291,999 Wilson et al Aug. 4, 1942 2,430,798 Alexander Nov. 11, 1947 

